This invention relates to cameras, and in particular to cameras with manually operated zoom lenses.
Zoom lenses have been available for expensive, manually operated cameras for some time. These lenses are typically operated by sliding an element axially along the barrel of the lens to change the relative positions of the optical elements to increase and decrease the magnification. More recently, zoom lenses have been incorporated into less expensive automatic cameras that automatically change the relative positions of the optical elements to increase and decrease the magnification. However, zoom mechanisms have generally been too complicated and expensive to incorporate into inexpensive cameras. Moreover, in a compact, inexpensive camera, conventional zoom mechanisms did not provide adequate or accurate adjustment. Another difficulty in incorporating a zoom mechanism in an inexpensive camera is that such cameras typically have view finders, and it is difficult to inexpensively alter the view through the view finder to accurately reflect the image captured by the lens system.
The camera of the present invention includes a compact, inexpensive, manually operated zoom lens system. The magnification of the lens system is adjusted by manual rotation of a part of the lens systems. More specifically, the lens system has at least first and second optical elements, the first optical element being movable relative to the second optical element. The lens system also includes a mechanism for moving the first optical element relative to the second optical element, and a rotatable element for operating the mechanism to change the magnification of the lens system. Thus, manual rotation of the rotatable element changes the magnification of the lens system, so that magnification of the image can be quickly and accurately adjusted. The lens system also includes an inexpensive and simplified shutter mechanism and flash actuator.
In accordance with the preferred embodiment of this invention, the camera also includes a view finder which displays an image generally representative of the image captured by the lens system. This view finder is preferably automatically adjusted with the change in the magnification of the zoom lens system caused by rotation of the rotatable element. In the preferred embodiment, the view finder comprises first and second optical elements, the first element being moveable relative to the second element to change the magnification of the view finder. The view finder also comprises a mechanism for moving the first optical element relative to the second optical element. This mechanism is preferably connected to the lens system so that as the magnification of the lens system changes, the magnification of the view finder changes accordingly. In the preferred embodiment, the optical elements of the lens system and the optical elements of the view finder are constructed and arranged so that as the elements of the lens system move in one direction, the elements of the view finder move in the opposite direction to maintain the view through the view finder generally in accordance with the image captured by the lens system. Thus optical elements are selected so that as the first and second optical elements of the lens system move toward each other, the first and second optical elements of the view finder move away from each other, and vice versa.
Thus the camera of the present invention provides an inexpensive camera with a zoom lens that is simple and easy to use. The user can easily and accurately adjust the magnification of the lens system to change the image captured by the lens system. Moreover in the preferred embodiment, the image viewed through the viewfinder automatically changes with changes in the magnification in the lens system so that the view finder accurately reflects the image captured by the lens system, in a non-single lens reflex camera.
These and other features and advantages will be in part apparent, and in part pointed out hereinafter.